1. Field of the Invention
This invention relates generally to a satellite antenna for use in a satellite communication system and, more particularly, to a method for installing and configuring a satellite antenna by defocusing the antenna's beam.
2. Discussion of the Related Art
Communication satellites are becoming an increasingly common means for delivering communication signals to consumers homes. Broadcast television systems are one example of satellite communication systems in the consumer market. TV programs are beamed from a central broadcasting station to a satellite(s), and then retransmitted from the satellite to a large number of ground-based users each having their own satellite communication terminal. Since these satellite terminals are being used as consumer products, they must be highly affordable and easily installed.
Geosynchronous orbiting satellites have the unique characteristic of constantly appearing at a fixed location (in the sky) with respect to the satellite's receiving ground station. During installation, the satellite's dish antenna must be pointed towards the satellite. Once the satellite's signal has been located and the pointing angle of the antenna is optimized for the strongest signal reception, the satellite antenna can then be secured in a fixed position with respect to the satellite.
Presently, satellite communication systems operate in the Ku band. At these frequencies, the satellite antenna must be accurately pointed at the satellite within 2 degrees to ensure signal reception. A typical consumer can practically accomplish this amount of accuracy during installation of their inexpensive, consumer class satellite antenna. However, a problem arises with future satellite communication systems that will operate at higher frequencies. For example, a satellite antenna operating in the Ka frequency band will provide about 1/4 degree of beamwidth. In other words, an antenna operating in a Ka band system requires eight times the pointing accuracy than an antenna operating in a Ku band system.
Due to this small beamwidth, it is considerably more difficult for a do-it-yourself consumer to install a satellite antenna. Locating the satellite's signal with a smaller beamwidth poses a significant challenge to a consumer having limited skills and tools. Furthermore, because the beam is so narrow, there is effectively no off-axis sensitivity. In other words, there is no variation in signal reception that allows for optimization of signal strength with respect to the near center of the beam. As a result, antenna installation will most likely require a trained professional having sophisticated tools, thereby increasing the consumer's cost to purchase and install such an antenna.
Therefore, a needs exists for a method to easily install and configure a satellite antenna. Locating the satellite's signal and optimizing the signal reception must be made practical for the do-it-yourself consumer. In addition, the solution must also be low in cost so that the total cost of the satellite antenna is affordable to the average consumer.